Spice service binary seems to be compiled to look for a device file called “/dev/virtio-ports/org.spice-space.webdav.0”, however there is no “/dev/virtio-ports/” in the first place:
strings /usr/bin/spice-webdavd | grep virtio-ports
/dev/virtio-ports/org.spice-space.webdav.0
systemctl status spice-webdavd.service
× spice-webdavd.service - webdav daemon for Spice guests
Loaded: loaded (/usr/lib/systemd/system/spice-webdavd.service; static)
Active: failed (Result: exit-code) since Mon 2021-08-09 09:04:24 EEST; 2s ago
Process: 8186 ExecStart=/usr/bin/spice-webdavd -p 9843 $SPICE_WEBDAVD_EXTRA_ARGS (code=exited, status=1/FAILURE)
Main PID: 8186 (code=exited, status=1/FAILURE)
CPU: 6ms
Aug 09 09:04:24 biv40b systemd[1]: Started webdav daemon for Spice guests.
Aug 09 09:04:24 biv40b spice-webdavd[8186]: Failed to open /dev/virtio-ports/org.spice-space.webdav.0: No such file or directory
Aug 09 09:04:24 biv40b systemd[1]: spice-webdavd.service: Main process exited, code=exited, status=1/FAILURE
Aug 09 09:04:24 biv40b systemd[1]: spice-webdavd.service: Failed with result ‘exit-code’.